I also don't understand this. AK4493 (v2) should have letter B, and also hole, the one coming to me has a slightly different looking hole (might be because of lighting), letter B, and larger remote. RME forums also say letter B stands for v2, and C for v3 (ESS).
Anyway, I'm unsure of my purchase (big surprise!) because many seem to point out the narrower soundstage in RME compared to similar products, some even say it has less details and is boring. Price was good, it was used. I can return it. Still looking if I can find something better (chinese brands?) for the price. I need DAC, pre-amp for my Genelec's (XLR), and decent headphone out. I guess 2 devices is still fine, but preferably all-in-one. 3 would be too much. I don't know if I need all the RME features, and if I'm paying for them. I also don't care about perfect accuracy. I care about the best perceived sound.